The present invention relates to a machine for processing of workpieces, comprising a worktable for the support of a workpiece, one or more tool assemblies for processing of the workpiece, and feeding and guiding means arranged to provide for positioning and simultaneous relative movement between the tool assemblies and the workpiece in a longitudinal as well as a transverse direction of the workpiece.
The invention especially deals with drilling and milling machines, and more particularly such machines of the so-called computerized numerically controlled type (CNC machines). Such machines are used within the industry especially for processing of workpieces of wood, and are provided with one or more tool spindles for contour or edge shape milling, for drilling or milling for fittings, for groove milling, etc.
There are previously known different types of CNC milling machines which all have in common that they are provided with a stationary worktable having removable vacuum cups or vacuum fastenings for the workpiece, and further are provided with a longitudinally and a transversely extending sliding guide for relative movement between the tool assemblies and the workpiece in a longitudinal direction (along an X axis) and a transverse direction (along a Y axis) of the workpiece.
The known machines are of two principal types: in one type, the longitudinally extending sliding guide moves the worktable on which the workpiece is fixed or clamped. In the other type, the longitudinally extending sliding guide moves the transversely extending sliding Guide in the X-axis direction along the workpiece, this being stationarily fixed in relation to the machine frame. In both machine types one is precluded from placing an underlying sliding guide with tool spindles below the workpiece, so that this, in these types of machines, cannot be processes from all six sides.
As mentioned above, the workpieces in the known machines during the processing are fixed to stationary worktables by means vacuum cups or vacuum fastenings. This is a substantial obstacle to being able to utilize such a machine in a rational way. The placing of the vacuum fastenings in relation to the workpieces is time-consuming, and one always must try to place these as close as possible to the processing site--the edge of the workpiece--in order to obtain a sufficient clamping. At the same time it has to be ensured that no fastenings are in the way of the milling tool.
When there is one or a small number of workpieces of the same size which is to be processed, this placing of vacuum fastenings will take a disproportionately long time of the total working time for each workpiece.
It should also be mentioned that the length of the workpieces is limited in relation to the machine length or the length of the worktable.